Well I know people who use the 18sqm miniwing also as kite up then ridge soaring and speed flying.. On video they say 6-12ms winds, ridge soaring on higher end. But the mountains are not that big in Finland - like videos of speedriding mnt Blanc etc. So nothing like that spectacular.

The snowkite video "Mountains of Wind" by Will Taggart had some scenes of snowkiting up and speed flying down. I think it was Pascal Joubert doing the speed flying.
Unfortunately, that fantastic video was removed after over 60K views. I found an abbreviated version here: http://www.alaskakiteadventures.com/201 ... ing-video/
If anyone has a link to the original video, please let me know.

I also recall a video from a few years back where I guy took off from a snowkiting area in the mountains and descended approximately 2000 feet into a town the whole time on his flysurfer foil. Not safe as any failure would have been fatal.